Pregnancy Due Date Calculator
Estimate a due date from the last period.
Results
Fill in the form and press Calculate.
Assumptions
- Naegele's rule: first day of last period + 280 days.
- Adjusted by (cycle length − 28) days.
- Only an estimate. Your healthcare provider confirms dating, usually with an ultrasound.
About this tool
Uses Naegele's rule (first day of last period plus 280 days), adjusted for cycle length. Only about 4% of babies arrive on the estimated date. Confirm dating with your healthcare provider.